In the manufacture of some automotive parts such as radiators and condensers, painting of the part is required for both appearance and corrosion-resistance reasons. In a conventional painting process, these automotive parts are conveyed through a paint spray booth for spray painting with no attempt to preheat the paint or the parts. As a consequence, the drying of these parts normally painted with a water-based paint takes place in a very long drying oven in addition to a 100 feet flash-off station. A length of 300-400 feet of drying oven is frequently required to sufficiently dry these parts.
Lengthy flash-off station and drying ovens are undesirable because they not only occupy extensive floor space area in a manufacturing plant, but also consume enormous amount of energy and require substantial manpower for maintenance. The excessive amount of time necessary to travel through the lengthy flash-off station and drying ovens is also a problem for achieving plant efficiency.
The method of preheating a part prior to its painting process has been utilized in the powder painting technology in which a dry powder paint is deposited on a preheated part such that the heat energy will help to melt and flow the dry powder paint in forming a paint film. The prior art method of preheating the part is, therefore, used for a completely different purpose than that taught by the present invention in that the heat energy in the preheated part is used to melt the powder paint into a paint film.
It is, therefore, an object of the present invention to provide a method of painting objects in which the solvent-containing paint can be quickly dried after the painting process.
It is another object of the present invention to provide a method of painting objects in which the solvent-containing paint can be quickly dried such that a short drying oven can be utilized